1. Field of the Invention
The present invention relates to improvement in an electronic control apparatus that includes a microprocessor performing drive control for an electric load group in accordance with the operation state of an input sensor group and the content of a program memory, and in which a specific sensor of the input sensor group has a label resistor for calibrating a device-variability variation in the detection characteristic of the specific sensor, or a specific load of the electric load group has a label resistor for calibrating a device-variability variation in the output characteristic, and relates to improvement in a control characteristic adjustment method for the electronic control apparatus.
2. Description of the Background Art
An electronic control apparatus is known in which: a specific sensor or a specific load is used which has a label resistor for calibrating a device-variability variation in a detection characteristic which is a relationship of measurement input-to-detection output of an input sensor, or in an output characteristic which is a relationship of control input-to-generated output of an electric load that is an electromagnetic actuator such as a motor or a solenoid; a microprocessor reads a resistance value of the label resistor; and the detection characteristic of the applied specific sensor or the output characteristic of the applied specific load is accurately recognized by the read resistance value.
For example, according to “GAS SENSOR, CONNECTOR OF GAS SENSOR, AND GAS CONCENTRATION DETECTION APPARATUS” of Japanese Laid-Open Patent Publication No. 11-281617 (see FIGS. 4 and 8 and paragraphs [0062] and [0065], hereinafter, referred to as Patent Document 1), as shown in FIGS. 23A to 23C, a label resistor RL is provided at a connector portion for external connection of a gas sensor that detects an oxygen concentration based on a first pump current IP1 (see FIG. 23A) and detects a NOx concentration based on a second pump current IP2 (see FIG. 23B), and ranks 1 to 36 are allocated on a two-dimensional map using six grades of correction coefficient β of −2, −1, 0, 1, 2, 3 for the first pump current IP1 and six grades of correction coefficient α of −2, −1, 0, 1, 2, 3 for the second pump current IP2 (see FIG. 23C). Then, one of the ranks 1 to 36 is specified by the resistance value of the label resistor RL, and as a result, the correction coefficients α and β are determined. Then, the oxygen concentration and the NOx concentration are detected by predetermined arithmetic expressions (1), (3), (4), and (5).
In addition, according to “INJECTOR AND FUEL INJECTION SYSTEM” of Japanese Laid-Open Patent Publication No. 2000-220508 (see FIGS. 14 and 18 and paragraphs [0064] and [0067], hereinafter, referred to as Patent Document 2), a correction resistor is provided on an injector so as to correct a device-variability variation included in the output response characteristic of a fuel injection electromagnetic valve. As shown in FIGS. 24A and 24B, in order to calculate an injection pulse period for determining a valve opening period of the fuel injection electromagnetic valve required for an instruction injection amount for obtaining a target fuel injection amount, a corrected injection pulse period characteristic indicated by a dotted line is generated which is obtained by algebraically adding first and second reference correction amounts to a basic injection pulse period characteristic indicated by a solid line in FIG. 24A.
For each of the first and second reference correction amounts, five grades of correction amounts of −20, −10, ±0, +10, +20 μs can be selected. Ranks 1 to 25 are allocated on a two-dimensional map using the first and second reference correction amounts (see FIG. 24B), and one of the ranks 1 to 25 is specified by the resistance value of the correction resistor.
The specific sensor of Patent Document 1 which is the gas sensor has a feature of being capable of determining the two types of correction coefficients α and β by one label resistor. However, each of the correction coefficients α and β is used for correction of a proportional gain GP1st(β) or GP2st(α) of the first pump current IP1 and the second pump current IP2, and an offset component IP2off of the second pump current IP2 is not corrected but a constant value is applied thereto.
Thus, a concept of performing correction, using a label resistor, for a detection characteristic including an offset component or a curved detection characteristic which is at least difficult to be represented as a linear line, is not shown, and in the case of such a complicated curved detection characteristic, characteristic data needs to be transmitted via an IC memory.
It is noted that, according to FIGS. 6A and 6B of Patent Document 1 showing the second embodiment thereof, a correction resistor Rc1 for adjusting the proportional gain of the first pump current IP1, a correction resistor Rc2 for adjusting the proportional gain of the second pump current IP2, and a correction resistor Rc3 for adjusting the offset current of the second pump current IP2 are used as circuit components of an amplifier circuit in a detection apparatus. In such a hardware style, there is a problem that noise malfunction can occur when a weak current signal circuit is connected to the outside of the detection apparatus or that the hardware cost of the detection apparatus increases.
In addition, the specific load of Patent Document 2 which is the injector merely corrects a device-variability variation in a response time of the fuel injection electromagnetic valve, but variability correction for a proportional gain which determines the relationship between the magnitude of an instruction current for the fuel injection electromagnetic valve and the injection pulse period is not taken into consideration.
In addition, a concept of performing correction by a correction resistor when the injection pulse period is not represented as a simple linear line, is not shown. In the case of such a complicated curved detection characteristic, characteristic data needs to be transmitted via an IC memory.